1. Field
Embodiments relate to a memory device, and more particularly, to a memory device including a circuit for measuring a read current of a memory cell, a test operation method of the memory device, and a system including the same.
2. Description of the Related Art
With the rapid development of the miniaturization of processes, variation in basic process parameters increases. The variation in the basic process parameters consequently leads to an increase of variation in transistor parameters and an increase of variation in memory characteristics, such as read current, write margins, and static noise margins.
Recently, a variety of techniques, such as read/write assist, for increasing memory cell reliability have been introduced. However, parametric yield loss has been increased due to the failure of a weak cell having a low read current. The result of measuring the read current of the weak cell using a silicon probe shows a significant deviation from the distribution resulting from memory test element group (TEG) measurement.
This fact indicates that the memory TEG measurement, which is performed on wafer scribe lines, is not statistically significant enough for accurate prediction about millions of memory cells. In addition, the measurement using the silicon probe consumes a lot of time and has low accuracy.